L-box, self-compacting concrete

The L-box is used to determine the passing ability and flowability of self-compacting fresh concrete. The method simulates how concrete passes through reinforcement under its own weight, providing a measure of the concrete’s ability to fill confined spaces without segregation of aggregate and mortar.

The equipment is manufactured in stainless steel and consists of a container with inner rigid surfaces and interchangeable grid sets for different reinforcement densities:

• Set with 3 vertical bars Ø 12 mm, clear spacing 41 mm — simulates dense reinforcement

• Set with 2 vertical bars Ø 12 mm, clear spacing 59 mm — simulates wider reinforcement

The equipment is also fitted with a guillotine-form gate for controlled and reproducible opening.